Dash-pot.



E. ERICKSON.

DASH POT.

APPLICATION FILED MAR. 15. m7.

Patented May 7,1918.

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EDWARD ERICKSQN, OF CLIFTONDALE, MASSACHUSETTS, ASSIGNOR T0 VICTOR SHOE MACHINERY COMPANY, OF LYNN, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

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Specification of Letters Patent.

Miginal application filed September 16, 1916, Serial No. 120,903. Divided and this application filed March 2'29 all whom it may concern:

Be it known that I, EDWARD ERICKSON, a subject of the King of Sweden, and a resident of Cliftondale, in the county of Essex and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Dash-Pots, of which the following is a specification. y

This invention relates to dash pots adapted particularly for use in connection with stop motions for power driven machines such as shown and described in another application of mine filed September 16, 1916, and numbered 120,903, of which this application is a division, said application having matured in Letters Patent No. 1,224,456, issued May 1, 1917.

The object of the presentinvention is the production of a dash pot which will be simple in construction and effective in its operation.

The invention consists in certain novel features of construction and arrangement of parts which will be fully understood by reference to the description of the drawing and to the claims hereinafter given.

The drawing represents a vertical section of so much of a machine as is necessary to illustrate the present invention.

For the purpose of illustrating the invention' one preferred form thereof is illustrated in the drawing, this form having been found to give satisfactory and reliable results, although it is to be understood that the vvarious instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described.

In the drawings, 10 is a portion of. the frame of a machine having a revoluble driving shaft 12 mounted in bearings in the upper end thereof. 7 This shaft has secured thereto a pulley provided with, a cylindrical hub 15 which extends into a chamber 16 in a cylindrical member 17 movable about the axis of the shaft 12. g

The frame 10 has an arm 20 extending laterally therefrom to which is pivoted at 21 a bell crank lever 22 one arm of which has mounted thereon a roller 23, while the other arm thereof has pivotally connected thereto Serial No. 155,107.

a rod 24 extending to a foot treadle which may be of any usual construction, and is therefore not illustrated in the drawing.

To ears 25 extending from the periphery of the chambered member 17 is pivoted at 26 a lever 27, the lower end of which is in the same plane with the roller 23 so that when the treadle rod 24 is moved downwardly the roller 23 will contact with the lever 27 and move it about its pivot 26. When the lever 27 is thus moved about its pivot, the lower arm thereof will contact with the head 28 of a pin 29 slidably mounted in the chambered member 17, said pin 29 normally being forced outwardly by means of the coiled spring or resilient member 31 interposed between the head 28 and the shoulder 30 formed upon the chambered member 17.

The inner end of the pin 29 is opposite to but free from contact with one end of a helical spring 32 surrounding the hub 15 of the driving member or pulley.

The opposite end of the spring 32 is positioned in a slot 33 in the movable member 17 and is prevented from being displaced therefrom by means of the plate 34 secured to the member 17 by means of the screws 35.

The helical spring 32 is formed in such a manner as to normally be in gripping contact with the periphery of the hub 15 and prevent the rotation thereof.

It is obvious that when the lever 27 is moved about its pivot by means of the roller 23, the inner end of the slidable pin 29 will come into contact with the end of the helical spring 32 and expand it sufliciently to release the gripping contact thereof upon the hub 15 and permit of its rotation independently of the movable member 17. The upper end of the lever 27 has a block 36 pivoted thereto at 37. Between the block 36 and a shoulder 38 on the lever 27 is interposed a spring jection it is positioned within the recess l3 it is obvious that the driving member 13 and the movable member 17 are locked together and prevented from accidental rotation.

When it is desired to rotate the shaft 12 the operator places his foot upon the treadle and depresses the rod thereby moving the lever about its aX' and :torcing the lower arm of the lever 11 against the pin 29. The inward movement of the pin 29 releases the gripping contact of the helical spring 32 upon tile periphery of the hub 15 nd the belt upon the pulley will then cause said pulley and the shaft 12 to be rotated in the direction oi the arrow at. The inward movement oi the lower arm of the lever 27 causes the upper arm thereof to be nioyed outwardly so that the projection so is disengaged from the locking recess i3 andas the cam member 1% rotates in the direction or the arrow a, the roller $6 at the upper end of the leverQi" rides up upon the raised track it and retains the projection it) free from contact with the periphery of the flange 14.

During the operation of the machine the operator retains his foot upon tne treadle. lVhen the loot is removed from the treadle, the tendency of the spring will be to force the pin 29 outwardly against the downwardly extending arm on the lever 52? and more the upper arm thereof" so that the roller so will travel along the track ea until it reaches the depression 4:5. The spring 80 will then cause the roller to more inwardly toward the axis 01"- the shaft 12 and permit the projection $0 to enter the recess 4:3 and stop further rotation of the revoluble driving members. I he bloch St; is adapted to move slightly about the pivot 37 aga nst th tension of the spring 39 when the propaction 520 is passing into the recess e3.

To prevent any shock when the loclnng mechanism stops the further rotation of the drivin members, a shock absorber is provided which consists of a dash pot 47 pivoted at $8 to toe frame 10 and having a piston e9 slidably mounted within the chamber 50 formed therein. The dash pot '1'? consists of a cup-shaped casing at? having threaded thereto a closure 4:8. The piston as has a rod 51 extending through the upper end of the dashpot t?! The upper end of the rod 51 is piyotally connected at 53 to the movable member 11 The shoulder is formed on the upper end of the rod 51 and between this shoulder 54: and" the upper end 52 oi the dash potei' is interposed a spring 55,

'which tends to retain the piston 49 in the position indicated in the drawing, at the upper end of the chamber 50. The lower end of the dash pot at? is provided with a passage 56 normally closed by means 03": a disk valve 57 formed of leather or similar ma terial nd normally positioned against the lower end of the chamber 50, as indicated in the drawing. This disk valve 57 is provided with an opening 58 therethrough offset from the passage 56. [he upper end of the dash pot a? is similarly provided with the passage oii set from an opening 60 in a disk valve 61 normally bearing against the upper end of the chamber 50. When the piston 49 mores downwardly in the chamber 50 the valve disk 5? will be slightly cupped at the beginning of the movement of said piston and the air within the chamber will be forced through the opening 58, then between the valve disk 57 and the wall of said chamber to the passage 56,) from which it" may escape;

is the piston l9 approaches the lower end of the chamber 50 the disk 57 will be fiat toned as indicated in the drawing, and the passage closed. When the piston 49 is moved downwardly a suction will be created above the said piston which will cause the dish Valve 61 to become cupped inwardly so that on the return movement of the piston the air within the chamber 50 will be forced through the opening 60 and passage 59.

This constructioniot shock absorber will effect an easy stopping or" the driving mechanism alwaysat a predetermined point inthe cycle of rotation of the driving members so that the machine is always when at rest in condition to inunediately start another operation as soon as the operator places his foot upon the treadle.

In order to more nicely adjust the dis charge of the air from the chamber 50 during the upward movement of the piston e9, the disk valve 61 is provided with opening 62 therothrough communicating with a passage 63 in the upper end of the dash pot ll. lhis passage 63 is provided wth a cone-shaped valve seat ol with which coacts the conical end or thereduced shank 65 of a member 65 threaded to the upper end of the dash pot ii. The passage 67 extends through the large end of the member 66 and communicates with the passage 63. By adjusting the member 66 any degree of opening of the valve may be provided. 7

The construction of the recess 43 and knockout projection 40 is such that when the foot is removed from the treadle and in the movement of the driving member 13 in the direction of the arrow a the recess 43 reaches a point opposite said projection tO,

said projection will immediately drop into said recess and permit the spring 32 to resume at once its normal position in gripping contact with the hub 15.

The member 17 will then become locked to the driving member 13' and both will move together in the direction of the arrow it against the tension of the spring 55 surrounding the piston rod 51.

As the piston i9 approaches the bottom of the chamber 50 or the dash pot 47, further movement oi the members 13-17 will be gradually stopped, and the spring 55 will then return these members 13-1? to the position indicated in the drawin This return movement will be gradual, owing to the slow escape of the air in the dash pot a? above the piston 49 through the discharge passages 60-59 and 62-63-67.

By means of this device the driving members may always be brought to a final stop at the same point and without any jar or shock to the various instrumentalities.

The inner wall of the casing a7 is provided with two annular grooves 68, each of which is provided with a flat side in the same plane with the inner face of an end wall or the casing, so that when the edge of a valve disk 57 or 61 is positioned therein, said dis: will be normally flattened against said end wall.

It is believed that the operation and many advantages of this invention will be fully understood from the foregoing description.

Having thus described my invention, 1 claim:

1. In a device of the class described, a cup-shaped casing having a central opening in its end wall and an annular groove formed in its inner cylindrical wall with one side of said groove in the same plane with the inner face of the end wall; a piston therein provided with a rod extending through said opening; a disk of flexible rnaterial with its edge positioned in said groove, said disk being provided with an opening therethrough of'set from a passage in the end wall of said casing; and a closure for said casin in a device of the class described, a cup-shaped casing provided with a closure at its outer end having a central opening in its inner end wall and an annular groove in its inner cylindrical wall, at each end of said casing, said grooves each having a flat side in the same plane with the inner face of an end wall; a piston in said casing provided with a rod extending through said opening; a disk valve in each annular groove, normally in contact with the inner face of said end wall and provided with an opening therethrough, ofiset from a passage in said end wall, one of said disks being provided with an additional opening therethrough; and means in said end wall for regulating the flow of material through said additional opening.

3. In a device 01' the class described, a casing the inner end of which is provided with a central opening and both ends of which are each provided with a passage at one side of the axis of said casing; a piston in said casing provided with a rod extending through said opening and having a shouldered head at its outer end; a spring around said rod between said head and casing and normally retaining said piston at the inner end of said casing; and a disk valve at each end of said casing provided with an opening therethrough ofiset from the said passage in the end wall of said casing, said disk valves being each alternately opened and closed by the movement of said piston.

i. In a device of the class described, a casing the inner end of which is provided with a central opening and both ends of which are each provided with a passage at one side of the axis of said casing; a piston in said casing provided with a rod extending through said opening and having ashouldered head at its outer end; a spring around said rod between said head and casing and normally retaining said piston at the inner end of said casing; a pivoted connection for the outer end of said casing; and a disk valve at each end of said casing provided with an opening therethrough ofiset from the said passage in the end wall of said casing, said disk valves being each alternately opened and closed by the movement of said piston.

Signed Mass, this 12th by me at a Post Ofice Sq., Boston,

day of March, 1917. EDlVARD ERIGKSON. Witnesses WALTER E. LOMBARD,

NATHAN C. LOMBARD.

Copies af this patent may be obtained for five cents each, by addressing the Commissioner oi. Patents, Washington, D. C. 

